The aim of this study was to examine the effectiveness of psychological resilience on friendship quality and emotional reactivity in children with oppositional defiant disorder (ODD). The research design was a quasi-experimental pre-test – post-test with follow-up and a control group. The statistical population of the study included all children aged 6 to 10 years with ODD in the 2025 academic year who were studying in schools in Tehran. The sample size consisted of 30 participants (15 in the experimental group and 15 in the control group), selected through convenient sampling and randomly assigned to the experimental and control groups. The psychological resilience intervention was administered to the experimental group, while the control group remained on the waiting list. The research instruments included the Children Symptom Inventory-4 (Gadow, Sprafkin, 1994), the Friendship Quality Questionnaire (Zahra-Vand & Hojazi, 2001), and the the affective reactivity Index (Stringaris et al., 2012). The data were analyzed using repeated measures analysis of variance (ANOVA) and SPSS 26 software. The results indicated that the psychological resilience intervention had a significant effect on friendship quality and emotional reactivity at both post-test and follow-up stages (p < 0.05). Therefore, based on the findings of this study, it can be concluded that enhancing psychological resilience can be an effective method for managing disruptive behaviors and improving social relationships in children with ODD.